A Quick, Easy, Cheap, Effective, Rugged and Safe method (QuEChERS) was modified to extract 15 pesticides, which are the most used in Egypt, in fish. Optimization was performed by Experimental Design expert 7.1 to get the best conditions. A new Gas chromatography coupled with a mass spectrometer (GC-MS) has been utilized for pesticides separation and quantification. In this study, the use of 200mg Primary secondary amine, 150mg C18 and 2ml chloroform were found to be the best conditions giving higher recoveries for extraction of the selected pesticides. The optimized QuEChERS method was applied to real samples of fish collected from different places of drainage water in Egypt in which residues of pesticides were detected.